New Mexico Snow

Senator Heinrich of New Mexico mentioned the declining snowpack in his home state during the senate’s recent all-night session about man-made climate change.

He was criticized in a comment at WUWT by Bill Parsons, who claimed that “Snow water Equivalent is up in 2014 between 20 – 30 % above the mean in nearly every NM drainage.” He even gave a link to some data to support his claim.

One of the lessons to be learned from Judith Curry is that when deniers give references to published papers or to actual data, claiming it supports their position, you damn well better look for yourself. Curry referred to half a dozen peer-reviewed papers to support her claim that Arctic temperatures in the 1930s may have been as high as they have been recently, but it turns out that none of the cited papers supported her claim. None. Bill Parsons linked to the update report on New Mexico snowpack to support his claim that NM snowpack is up in 2014, but it turns out that the update report says exactly the opposite. Opposite.

Even so, we’re far less interested in short-term events like the disturbingly low snowpack in New Mexico right now. We’re more interested in the trend, as a better indicator of whether or not changes are truly meaningful, and whether or not they may be a harbinger of worse to come. So, let’s look at trends in snowpack in New Mexico.

Daily data on SWE (snow water equivalent) in the snowpack can be obtained from SNOTEL. There are 26 SNOTEL stations in New Mexico, but only 13 of them have data since 1990 or earlier. Even that is not a very long time span, so any trend will have to be very strong in order to be detected. Let’s look anyway.

Here’s an example, the SWE at the Quemazon site:

It peaks each winter, then melts away each spring. But visually, it looks as though the peak amount has been declining. We can test that idea by noting the maximum value during each snow season, then testing whether or not there’s a significant trend. It turns out there is:

Annual maximum SWE has been declining at about 0.2 in. per year; over the 30+ years of record, the mean value has decreased by over 6 inches. In other words, it’s now only about half what it was in 1980. And that’s not just this year’s fluctuation — that’s the trend.

Lest anyone think you have to cherry-pick the Quemazon site to get such a result, you don’t. Of the 13 SNOTEL stations in New Mexico with data since 1990 or earlier, 10 show a statistically significant decline in snowpack while none show a statistically significant increase.

The snow is also melting out earlier in the year. I fit a smooth curve to the SWE data and determined, for each year, the time at which it was declining fastest — we can call this the “max melt day.” This too shows statistically significant decline at Quemazon, receding by 0.76 days/yr:

All told, maximum snowmelt at Quemazon is happening about 24 days earlier now than it was in 1980. Again, this is not just happening at Quemazon, it’s typical of the state of affairs in New Mexico.

Water is essential for all life. Changing the amount of water available, and shifting the timing at which water is available, is bound to have serious consequences for all living things, not just in New Mexico, but everywhere that man-made climate change is altering the hydrological cycle. In fact, changes to the hydrological cycle might just be the single most dangerous aspect of global warming.

One of the life forms most threatened by climate change, is the life form which has caused it to happen: humankind. We are also the only life form which can make the choice actually to do something about it. I say, let’s make that choice.

32 responses to “New Mexico Snow”

And it’s not just New Mexico… The University of Idaho has an active research program on the range of Climate Change Issues in the Northern Rockies: http://projweb.cals.uidaho.edu/northernrockies/ and I’m sure there are other schools as well…www.cfc.umt.edu/CCS/, for example. The pattern of earlier snowmelt is common throughout the west and is closely linked to the earlier start of the fire season…and its longer duration into the fall.

I thought, maybe, it *could* have been a mistake, something like the data was expressed as % of median, and it was misinterpreted as meaning 50% was median. But even being that generous, I only get 3 out of 13 sites at 20% ‘above median’. Crazy. Even deliberately misinterpreting the data, I can’t replicate the WUWT result, which leaves outright fabrication as the most plausible explanation.

The SNOTEL site isn’t working right now, so I don’t remember the exact column headings, but they were something like % of median and % of peak, and they were side by side. Of course the % of median was bigger in every single case; it has to be.

Now this is just a shot in the dark, but I’m guessing this guy looked at the bolded figures and saw that the numbers in the left hand column were bigger than the right hand column and ignorantly, stupidly, maliciously, fill in the blank-ly, said that the columns were today’s value and the historical median. And the one on the left was bigger every time! How convenient for his talking point.

Tamino, a stats question: is ANCOVA the correct way to analyze the data and get the overall significance across locations?

[Response: I think ANCOVA would be a way to explore whether or not there are differences between different basins. As for individual sites, there’s only one time series for each. To get significance, analyze each series individually.]

What question are you trying to answer? Are you trying to estimate the total water available in the form of winter snow packs which drains into the relevant basin? If so, do these sites provide the adequate and random coverage to answer that question? If they do, then aggregating would be reasonable in my opinion as the sum would estimate the variable of interest.

But I’m not sure that’s really the question of real interest to the residents.

We moved to Albuquerque, New Mexico just this past November. We did it knowing full well the water situation in the Southwest. We chose Albuquerque because the city gets it’s water from the Colorado, and not wells like other parts of the State. I heard but am not certain, that Santa Fe, N.M. (A city of 70,000) gets their water from the New Mexico snow pack and not from the Colorado River. Of course the situation is dire for the Colorado River too, but the water supply for people here in Albuquerque is more stable than for those that rely on wells, or Northern New Mexican snowpack. (Santa Fe)

Climate Central had a story a week or so ago about how New Mexico looks like it could have an explosive wildfire season. Apparently the mountains that border the eastern part of the city (the Sandias) are quite vulnerable to wildfire and Albuquerque has been lucky that hasn’t happened, at least for a very long time. The wealthiest homes in Albuquerque are all located up in those mountains, or in the foothills. I don’t think the people who live there have much of a sense of the danger from wildfires to them. We are lucky enough to be located farther down the valley, and supposedly are not in much danger of fires, but we are still located close enough to the mountains to make me nervous. This is a very poor State and I’m afraid resources will be lacking in the future to protect the citizens from climate change. My biggest fear is drought and heat waves resulting in prolonged power outages, but at least Albuquerque is at a very high elevation and cools off dramatically at night. This isn’t Phoenix or Las Vegas.

Perhaps I should be worried about the reliability of water as well, even here in Albuquerque.

Santa Fe’s municipal water supply comes from the Santa Fe river watershed in the Sangre de Cristo Mts east of the city; from groundwater wells in the alluvial deposits of the Rio Grande rift, which are supplied by run-off from a wide area of the Sangres; and directly from the Rio Grande river, which is now being augmented by the San Juan-Chama project, whereby Colorado river water is transferred to the Rio Grande through a tunnel under the continental divide.

You should have done more research about water rights in the southwest.

Santa Fe is actually doing a better job of securing water and water rights than Albuquerque. While Albuquerque has the convenience and beauty of the Rio Grande following through the city, it has only junior, or more recent water rights to the river. This means senior or older claimants are entitled to all of their water rights before Albuquerque gets a drop of water. In a drought the city will have to helplessly gaze upon the river, all of whose water will be owned by and owed to others.

Santa Fe, on the other hand, has diversified its water portfolio extensively: roughly a third still comes from snow pack and is held in upstream reservoirs, a larger yet chunk comes from a number of local wells, some held in reserve, and, via a Colorado tunnel under the Rockies, the city has purchased water rights to both Colorado River and Rio Grande water. The Colorado water is dumped into the San Juan, follows downstream to the Chama, and thence to the Rio Grande where the recently completed Buckman diversion brings it into the city itself.

In addition Santa Fe has purchased wide ranging “paper” water rights that can be traded for upstream water. This, plus progressive pricing (the more water you use the higher your per gallon cost is), will almost certainly keep Santa Fe from running out of its water.

On the other hand Albuquerque has much lower fire risks than Santa Fe since the Sandias are sparsely forested compared to the Sangre de Christos above Santa Fe. The dominant pines in the Sandias are also fire resistant Ponderosas rather than the young ‘dog hair’ firs common to the Sangres.

An off-topic heads-up on a piece of statistical analysis I stumbled across that might be of interest. It is being wielded by Barking Lord Monckton of Brenchley.
He performs a least squares analysis of RSS monthly global temperatures August 1996 to February 2014. The calculation actually yields a slope of 0.0031C – ten times flatter than the Viscount suggests. (If he was a Count (careful with the typos), perhaps he would be better experienced at placing decimal points and thus not require an Australian Professor of Epidemiological Statistics to fail to spot the error for him.) And r-squared is 8.9 x 10^-7 which is very close to the zero value His Lordship presents.

What intrigued me was not the banal result, or even why somebody would be so prompt at spotting it – he writes up his results “just hours” after the RSS data is posted. Rather, it is the strange description of the Least Squares calculation which seems inexplicable to my humble eyes.“…the method of least-squares linear regression, which determines the y-intercept and slope of the line via two well-established and functionally identical equations that are compared with one another to ensure no discrepancy between them.” What the blazes is that all about?

This right-wing penchant for giving citations that don’t support the claims being made has a long history, which would be a good topic for study (perhaps there is such a study – I would like to know). I believe Ann Coulter, for example, has published mock-scholarly books full of footnotes that contradict what she claims they say, but I’m sure she’s not the first. As far as I can tell, the idea is that it gives the veneer of scholarship, which comforts the believers and persuades the fence-sitters, but anyone who would go to the trouble of checking the citations is not among the intended audience anyway. At first I thought it ws a brilliant strategem, but then it occurred to me that an unscrupulous college student under time pressure to produce a term paper could easily come up with the idea. I almost regret that I didn’t think of it myself.

Turns out you CAN “match” the curves. If you do so you “see” immediately that while arctic ice anomolies are still decreasing, the decrease is either much slower or is part of “just natural cycles”. Winter extent in particular. In doing so, however, you have to neglect 3 minor points:

1. A lot of unreachable areas were simply assumed to be 100% covered.
2. Unlike present extent definitions, the Gulf of St. Lawrence and Baltic areas were excluded from their analysis (no ice extent in either of those areas–especially in winter where Goddard is trying to make much of his point!).
3. Extent was defined by W&J as the sum of the products between ice cover ratio and the area of each grid point rather than the present “> 15%=100%” rule.

I’m sure that failing to communicate these totally trivial methodological points–ALL of which would tend to negate his point–was a mere technical oversight. Peer review would easily catch this, but of course his blog is not peer reviewed.

[Response: Nobody in his right mind would take Steve Goddard seriously.]

John – In an all too public display of insanity we’re currently peer reviewing Mr. Goddard’s more recent statements about Arctic sea ice. Thus far he has failed to answer 9 out of 10 questions in our brief examination of his basic scientific knowledge on the subject. His answer to the other one consisted of one image, but no words. Not even his trademark ROFL!

And yet, Dennis Bray, of the Institute of Coastal Research, has decided to give Steven Goddard so much credibility that he uses him as a source to “debate” a rebuttal with reference to NOAA to Bray’s original claim on Klimazwiebel that the US has seen its third-coldest winter.

Well Nate recently advertised for people: “First, and most important, we’re looking for freelance features and articles that involve original research, analysis, or reporting — specifically those that involve statistical analysis, data mining, programming, data visualization, or other data-journalism methods.” and also with much work under their own byline. Unfortunately Pielke certainly has “experience” in all of these. Just not very honest experience.

I cannot imagine Nate will really put up with him for long once he actually gets feedback on his actual work–unless he’s looking for a controversial source guaranteed to generate page hits–but we’ll see.

I got curious, whether the reported anomalies were an artifact or real and replicated the plot using the current timeseries. The anomalies were real, but I found a bug in McI’s script in the process; the script erroneously swaps two column labels. His reported area (anomaly) is actually extent and vice versa. I was mildly amused that the bug has gone unnoticed by McI and his auditors.

Yes. Way, way too many people are “not in their right minds”–by Tamino’s cogent and spot on definition of the term(!)–unfortunately.

It never ceases to amaze me that people make arguments about “countertrends” that are occurring entirely inside 2 or even sometimes < 1 sd of the predicted scatter about a computed trend line. Essentially, that is what the "recovery" last fall was about (as well as the records/new records now for that matter to be fair). That is what the so-called "hiatus" is all about statistically too.

So 30 Years in a well known warming period is no Cherry pick? Where is the data from the rest of the 20ieth Century?

[Response: Since you clearly don’t know what a “cherry pick” is, let me set you straight. Using all the data available is NOT a cherry pick. If you know where to get more, do tell.]

The discussion for me should predominantly based on data and not this fruitless personel bickering that i see here going on and on.

[Response: This discussion is based on data. In fact, it’s purpose is to show that the criticism of senator Heinrich’s comments are contradicted by the data.

How ingenious of you — perhaps I should say ingenuous — to take a post based on data, then criticize it by proclaiming that the discussion should be based on data. Then you add a reference to “bickering.”]

Am i the only one who feels that way or is everybody else being driven away already?

As my son says, when being polite “what the, what the? I was not a happy camper when Tamino disappeared for quite a while this past year. I come to this site to see deep statistical analyses of climate change. The “bickering” is often over fine points of statistics, and I always find that quite educational, and quite often entertaining as well.

When people make the mistake of baseless, poorly thought out attacks, then Tamino rightfully responds.

I’ve not read Tamino professionally, and am a newcomer, but climate statistics are what I’m all about. Given the “one shot” nature of “our global experiment” I think my Bayesian sympathies and skills are particularly appropriate, sympathies which many others have embraced, e.g., Berliner. Don’t know Tamino’s view.

Still working on that precipitation index data,BTW.

[Response: My background is frequentist, and I object to claims that it has no place in modern statistics. But I regard the Bayesian approach as in many ways inherently superior.]

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